To simplify the following discussion, the present invention will be explained utilizing optically-based communication systems. However, the present invention can also be utilized in a wide range of other applications as will be discussed in more detail below.
The ever-increasing bandwidth requirements of communication systems have resulted in data being transmitted over optical fibers. Both conventional telecommunications and data networks such as the Internet utilize optical fibers for long distance transmission. Data is sent by breaking the transmission into data packets that are routed between the sender and receiver with the aid of switches that route packets between fibers and/or channels within a single fiber.
While the transmission of the data is performed optically, the switching of the data must often be performed by converting the optical signals to electrical signals. The electrically-based data packets are then re-arranged using an electrically-based cross-connect switch. The re-arranged electrically-based packets are then converted back to optical signals. The electrically-based switches typically switch packets between a plurality of input channels and a plurality of output channels. Data from each input channel is stored in a cache memory. The data packets for each output channel are then assembled by reading the data stored in the cache memory.
While optical communication channels provide data rates in excess of 10 Gbits/sec at relatively modest costs, electrically based circuitry that can operate at these high data rates are either non-existent or very expensive. For example, the electrically based packet switches discussed above must utilize a highly parallel architecture to make up for the relatively slow operating speed of the memories and data routing circuitry to obtain the needed throughput. Such circuitry is complex and costly.